Governor for internal-combustion engines



Dec. 30, 1952 A. S'CHWEIZER 2,623,510 GOVERNOR FOR INTERNAL-COMBUSTION ENGINES Filed July 11, 1949 "0 "max INVENTOR ALFRED SCHWEIZER ATTORNEYS Patented Dec. 30, 1952 UNITED STATES TENT OFFICE.

GOVERNOR FOR INTERNAL-COMBUSTION ENGINES Stuttgart, Germany Application July 11, 1949, Serial No. 104,114 In Germany October 10, 1948 2 Claims.

The invention relates to a fuel governor arrangement for fuel injection internal combustion engines having external ignition means, of the type in which the fuel injection pump is controlled by an element, under the influence of a difference in pressure between the atmosphere outside of the engine manifold, and pressures at places before and behind a throttle valve in the air induction manifold.

Internal combustion engines operating with external ignition means require an especially rich mixture when idling or when under light load. This requirement is satisfied by the arrangement of the present invention in a very simpl manner in that at least one of the places used as a source of pressure is disposed on the upstream side of the throttle valve controlling the air intake, and in front of the air entry point where that part of the throttle valve moves in a direction opposite to the direction of flow of the air as this valve opens, and immediately adjacent to this part, so that the pressure at this point upstream of the throttle valve can, as this opens, alter, to an ever increasing degree, the controlling effect of the reduction in pressure produced by the runnin of the internal combustion engine.

The invention is further described with reference to the accompanying drawings which illustrate two forms of construction of the invention by way of examples, and in which:

Fig. 1 is a diagrammatic part sectional elevation of a fuel governor device according to one form of construction, and

Fig. 2 is a diagram illustrating the method of operation of this example,

Fig. 3 is a view of the second form of construction, and

Fig. 4 is a diagram illustrating the method of operation of the example shown in Fig. 3.

Referring first more particularly to Fig. 1 of the drawings, a cam shaft I I driven by an external ignition fuel injection internal combustion engine (not shown) and actuating a pump piston I2 is mounted in the housing 10 of a two cylinder fuel injection pump. The pistons can be rotated about their axis by means of a rack or toothed rod [4 and according to the degree of this rotation deliver more or less fuel into the working cylinders of the internal combustion engine. The rack I4 can be adjusted by a diaphragm l5 which constitutes the adjusting member of the governor device. This diaphragm is accommodated in a housing built on to the pump, which housing is divided into a control pressure chamber 16 and a chamber I8 in communication with the atmosphere through an orifice I 1. Chamber I6 is connected through a pipe 59 with a branch passage 20, the mouths 2! and 22 of which form two pressure taking points which are located respectively, in the examples of Figs. 1 to 4, in front of and behind a throttle valve 2%, said valve being positioned in the induction pipe 25 leadin to the engine.

The quantity of air fed to the engine, and in consequence thereof the predetermined pressure on the downstream side of the throttle valve 24, controlled by this valve. Should the pressure on the downstream side of the valve, that is to say the suction pressure, remain constant for a considerable number of revolutions of the engine, then as the revolutions increase, so must the throttle valve be fully opened. In consequence, the pressure at the opening 2|, which with the throttle valve fully closed is substantially that of atmospheric pressure, will approximate to the suction pressure. An intermediate value of pressure is thereby established in th branch pipe 20 and will be operable upon the membrane 15. This intermediate pressure value, acting in conjunction with the uniform atmospheric pressure in the chamber 18, will, with constant suction pressure and a rising rate of revolution of the engine, operate with increasing effect to reduce the output of the injection pump, by action on the diaphragm i5 loaded by the helical spring 26. The strength of the control force on the element M- in relation to the speed of revolution of the engine can be adapted to suit requirements by suitable dimensioning of the cross-section of the openings 2| and 22, which if necessary can be further adjusted by throttle screws 27 and 28, and the position of the opening 2|.

In order to fulfill the heavy requirement of an especially rich mixture for the internal combustion engine when this has been idling or running under light load, the opening 2| is disposed in front of the air entry point where that part of the throttle valve moves in a direction opposite to the flow of the air as this valve opens, and immediately adjacent to this part of the throttle valve, so that the pressure at the opening 2 ll, that is to say the amospheric pressure, when the throttle valve is shut, or almost so, as the throttle valve progressively opens, will have an increasing effect on the reduction in pressure produced by the internal combustion engine. The force operating the fuel adjustment is therefore small at low speeds of revolution of the engine, and effects only a small displacement of the control rod 14 in the closure direction, and thus ensures a rich mixture.

The above mentioned operation is indicated diagrammatically in Fig. 2. In this diagram the line a indicates the constant course of the atmospheric air pressure, and the dotted line b shows the pressure course (induction pressure) in that part of the pipe 25 on the downstream side of the throttle valve in which the opening 22 is located; if the loading of the engine remains constant, this pressure course likewise remains constant. The pressure in front of the throttle valve 24 or at the opening 21 of the branch passage 20 is, at the lowest speed of the engine no with the throttle valve almost closed, approximately equal to the atmospheric pressure; at the maximum engine speed max, 1. e. with the throttle valve opened correspondingly wide, it is almost equal to the pressure at the opening 22. At a result of the pressure difference present between the two openings, there arises in the branch passage 20 an intermediate pressure, the course of which roughly corresponds to the line 01. The sectors q of the ordinates limited by the lines a and b indicate the adjusting force which increases at constant loading with increasing engine speed and thus acts or operates towards a movement of the governor rod H! in the direction of closure.

In the embodiment shown in Fig. 3, apart from the two openings 2| and 22 which are in communication with an annular channel 40, there is also provided an additional or supplementary opening Zia. This arrangement necessitates a path or course of the adjusting force q illustrated diagrammatically in Fig. 4.

The alteration from conditions for a rich mixture to conditions for a weak mixture is not so rapid as in the case of the first example of construction.

I claim:

1. In a fuel governor for or fitted to an external ignition injection internal combustion engine, a control chamber, an adjusting member in said control chamber adapted to control the fuel delivery, and connections from said control chamber to the induction duct of the engine at opposite sides of a throttle valve in said duct, one of said connections being on the upstream side and one of said connections being on the downstream side of that part of said throttle valve which moves in a direction opposite to the direction of flow of the air as said throttle valve opens.

2. In a fuel governor for or fitted to an external ignition injection internal combustion engine, a control chamber, an adjusting member in said control chamber adapted to control the fuel delivery, connections from said control chamber to the induction duct of the engine at opposite sides of a throttle valve in said duct, one of said connections being on the upstream side and one of said connections being on the downstream side of that part of said throttle valve which moves in a direction opposite to the direction of flow of the air as said throttle valve opens, said connection on the upstream side of the throttle valve being located immediately adjacent to said part of said throttle valve.

ALFRED SCHWEIZER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,132,446 Schweizer Oct. 11, 1938 

